I have this theory

I’m Just saying cuz the last panel with him saying, “how long has it been since we’ve been able to sleep as soundly as this” made me very sus

If That’s true Ima loose my shit yooo

I was thinking the same thing but then I saw Kairi’s back and it seems he doesn’t have the burn scars, also it’s be weird if he knew that was his sister and was doing it with her (but maybe he developed a psychological disorder where he took on someone else’s identity)

I mean that would have been a heck of a plot twist and a great one at that but i doubt it... I mean they both look different and Kairi doesn’t has scars and also we saw Kairi’s background story so like it’s nothing like that. I think when he means “ how long has it been since we’ve been able to sleep as soundly as this” i think what he meant was like after all they both have been through a lot and yk they once just slept together in the bed or something in the beginning of the manga and i think Kairi mentions that time as relieving because they both slept soundly for the first time together back then and this as the second time after so many shit happening between those two. I Don’t think the plot would go even more twisted and for some reason i think we are getting closer to the end a bit. Like im sure Kairi is going to be known as the murderer... sadly even tho i dont want that ik in fact that something big is about to go down and well ye let’s just hope for good and happy stuff...

They used to sleep together though in the beginning of the story, that's what they meant. He's not her brother.

That’s not possible though. There are visible differences between the child brother that she remembers and the one she likes. Plus, obviously they mean that their anxiety has been relieved. That’s why they can sleep soundly

Does that mean she slept with her brother T-T